This text examines the six principal types of electoral system currently in use in more than fifty of the world's democracies: single member plurality, alternative vote, two round systems, list, single transferable vote, and the currently fashionable "mixed" systems. A common format is adopted throughout, dealing with explanations of how the system operates and its effects on the political system. The book concludes by assessing the effects and consequences of electoral systems, the factors behind their selection and the question of whether there is a "trade off" between proportionality and stability.